At the closest point, asteroid 2004 BL86 will be 1.2 million kilometers which – about three times the distance from the Earth to the moon, at 11:19 a.m. ET, according to NASA.(Nothing to sneeze at.) Estimated to be 0.5 km in diameter, it is classified by scientists as potentially dangerous.

It will be the closest known asteroid this large to pass near Earth until 2027, that's when an asteroid called 1999 AN10 flies by us.

You can watch it live, here.

Learn more here, from NASA.